Fibroproliferation occurs early in the acute respiratory distress syndrome and impacts on outcome

The fibroproliferative phase of acute respiratory distress syndrome (ARDS) has traditionally been regarded as a late event but recent studies that suggest increased lung collagen turnover within 24 h of diagnosis challenge this view. We hypothesized that fibroproliferation is initiated early in ARDS, characterized by the presence of fibroblast growth factor activity in the lung and would relate to clinical outcome. Patients fulfilling American/European Consensus Committee criteria for ARDS and control patients ventilated for non-ARDS respiratory failure underwent bronchoalveolar lavage (BAL) and serum sampling within 24 h of diagnosis and again at 7 d. The ability of BAL fluid (BALF) to stimulate human lung fibroblast proliferation in vitro was examined in relation to concentrations of N-terminal peptide for type III procollagen (N-PCP-III) in BALF/serum and clinical indices. At 24 h, ARDS lavage fluid demonstrated potent mitogenic activity with a median value equivalent to 70% (range 31-164) of the response to serum, and was significantly higher than control lavage (32% of serum response, range 11-42; p < 0.05). At 24 h, serum N-PCP-III concentrations were elevated in the ARDS group compared with control patients (2.8 U/ml; range 0.6-14.8 versus 1.1 U/ml; range 0.4-3.7, p < 0.0001) as were BALF N-PCP-III concentrations (2.9 U/ml; range 0. 6-11.4 versus 0.46 U/ ml; range 0.00-1.63, p < 0.01). In addition, BALF N-PCP-III concentrations at 24 h were significantly elevated in nonsurvivors of ARDS compared with survivors (p < 0.05). At 7 d, the mitogenic activity remained elevated in the ARDS group compared with control (p < 0.05) and was also significantly higher in ARDS nonsurvivors compared with survivors (67%; range 45-120 versus 31%; range 16-64, p < 0.05). These data are consistent with the hypothesis that fibroproliferation is an early response to lung injury and an important therapeutic target.

Current strategies for mechanical ventilation in acute lung injury

Non-invasive modes of ventilation may be adequate for some patients with less severe acute lung injury (ALI) but invasive positive pressure ventilation is usually required. Ventilation strategies for such patients have changed significantly in recent years, as it is has become increasingly apparent that the process of ventilation itself may contribute to lung injury.

Distress experienced by participants during an epidemiological survey of posttraumatic stress disorder

We examined the potential for epidemiological studies of mental disorders, specifically of posttraumatic stress disorder (PTSD), to cause further harm to participants involved. Of 1,000 randomly selected Australian Vietnam veterans, 641 agreed to participate in an epidemiological survey. Participants were asked about distress experienced during the interview when traumatic events were raised. Significant distress attributed to the interview was reported by 75.3% of those with current PTSD, 56.5% of those with past PTSD, and 20.6% of those with no PTSD diagnosis. Distress did not affect participants' use of medical services following the interview nor did it affect their willingness to continue participating in the study. We concluded that research interviews about PTSD may cause short-term distress, but found no evidence of long-term harm.

Angiotensin II is mitogenic for human lung fibroblasts via activation of the type 1 receptor

The expression of renin-angiotensin system components and the elevation of angiotensin-converting enzyme (ACE) in a number of fibrotic lung diseases suggests angiotensin II (AII) could play a role in the pathogenesis of pulmonary fibrosis. However, the effect of AII on lung fibroblasts has not previously been assessed and the mechanisms by which AII induces cell proliferation in mesenchymal cells are not fully understood. We have examined the ability of AII to stimulate fetal and adult human lung fibroblast proliferation in vitro. In particular, we have assessed the receptor subtypes involved and the possible autocrine role of transforming growth factor beta (TGF-beta) and platelet-derived growth factor (PDGF), two recognized fibroblast mitogens. Angiotensin type 1 (AT1), but not type 2, receptors were identified on fetal and adult human lung fibroblasts by immunocytochemistry. AII (1 microM) increased DNA synthesis (determined by [(3)H]thymidine incorporation) in fetal and adult cells by 211 +/- 18% and 150 +/- 14%, respectively (p < 0.01), and was inhibited by a specific AT1 receptor antagonist, Losartan (74 +/- 14%). A proliferative response to AII was confirmed by direct cell counts. Subsequently, fibroblasts were incubated with neutralizing antibodies to TGF-beta and PDGF. Anti-TGF-beta antibodies inhibited AII-induced DNA synthesis by 73 +/- 13%. However, no effect was seen with anti-PDGF antibodies. In conclusion, we have shown that angiotensin II induces human lung fibroblast proliferation in vitro via activation of the AT1 receptor and involves the autocrine action of TGF-beta.

Adult familial cryptogenic fibrosing alveolitis in the United Kingdom

BACKGROUND

Familial cases of cryptogenic fibrosing alveolitis (CFA) have previously been reported; however, the prevalence and genetic background of this disorder are not known. The clinical and epidemiological findings of 25 families identified within the UK are reported.

METHODS

Adult pulmonary physicians in the UK were asked to identify all families under their care in which two or more individuals had been diagnosed with fibrosing alveolitis of unknown cause. A detailed structured questionnaire was sent to each proband to delineate possible environmental/occupational exposures and to obtain complete pedigree data. Physicians were also asked to provide clinical and diagnostic information.

RESULTS

Twenty five families were identified comprising 67 cases. Suitable data for analysis were available for 21 families (57 cases). The male:female ratio was 1. 75:1 (p<0.05). A high resolution computed tomographic (HRCT) scan was performed in 93% and a diagnosis of CFA confirmed on biopsy specimens in 32%. The mean age at diagnosis was 55.5 (2.5) years. Fifty percent of cases were ever smokers and 18% had been diagnosed as asthmatic. Exposure to known fibrogenic agents was recorded by 36% of patients. Clinical signs/symptoms and histological findings were indistinguishable from non-familial cases.

CONCLUSIONS

This study represents the largest cohort of familial CFA cases reported to date and confirms a prevalence of 1.34 cases per 10(6) in the UK population. Although rare, such cases represent an important subgroup in which a genetic susceptibility to pulmonary fibrosis is particularly evident. Familial patients are younger at diagnosis but otherwise indistinguishable from non-familial cases. The mode of inheritance is as yet unclear but a number of genetic loci are likely to be involved and are the subject of ongoing studies.

Combat, dissociation, and posttraumatic stress disorder in Australian Vietnam veterans

The specificity of various wartime stressors for different posttraumatic stress disorder (PTSD) symptoms is inconsistently reported in the literature. Combat, wounding, and peritraumatic dissociation have not been assessed together in their effects on each of the various PTSD symptom clusters. This cohort study of a random sample of male Australian Army Vietnam veterans yielded psychiatric assessments of 641 subjects. PTSD measures comprised symptom criteria for reexperiencing, numbing and avoidance, hyperarousal, and PTSD diagnosis both lifetime and current within the past month. Logistic regression is used to examine the effects of combat, wounding, and peritraumatic dissociation together on PTSD. Combat experiences comprised four components derived from a principal components analysis of combat experiences: direct combat exposure, exposure to death and injury, exposure to civilian death and injury, and exposure to mutilation. Each was differentially related to reexperiencing, avoidance, hyperarousal, and PTSD diagnosis. Being wounded was not related to lifetime or current PTSD and peritraumatic dissociation was related to all diagnostic components of PTSD in the presence of other variables.

Posttraumatic stress disorder and other predictors of health care consumption by Vietnam veterans

A total of 641 randomly selected Australian veterans of the Vietnam War were interviewed about their use of health care in the previous two weeks to determine what factors contributed to health care consumption. Seventy-three variables were examined by univariate linear regression and then grouped into seven categories relating to age, physical and mental health, predisposition to posttraumatic stress disorder (PTSD), deployment and repatriation experiences, and membership in veterans groups. PTSD was associated with an additional cost of $79 in health care for the two-week period. Each physical diagnosis was associated with an additional $28. Alcohol consumption was not related to health care costs. Other important variables contributing to costs were depression, educational status, the quality of the repatriation experience, and social support.

DRG cost weights--getting it right

Inadequate cost weights are a major problem in casemix funding systems. Clinicians should understand the basis for the cost weights underpinning the hospital payment system in their State and their own hospital. Clinician managers need valid patient costing data if they are to benchmark and improve cost-effectiveness while maintaining and enhancing quality. The cost model approach for determining cost weights has inherent limitations, and, the alternative, detailed patient costing, requires efficient hospital information technology systems. A simplified approach to patient costs, which uses existing hospital data systems, may be useful for smaller hospitals. A better classification system and funding formulas incorporating reliable cost weights derived from patient costing should overcome many of the deficiencies in the current casemix payments systems.

Postwar experiences and treatment-seeking behavior in a community counselling setting

Previous research investigating the impact of postwar experiences on Vietnam veterans has focused on veteran morbidity. This emphasis has meant that the impact of these factors on treatment-seeking behavior has received little empirical attention. This study examined the association between postwar factors and treatment-seeking behavior in a sample of 692 Australian Vietnam veterans. Logistic regression analyses were used to compute the odds ratios associated with postwar experiences and self-referral to a community-based counselling service. Results suggest that veterans who reported experiencing negative feelings toward others when they first arrived home were more likely to seek treatment. Other factors, such as a veteran's perception of societal attitudes and the reception they received, were not associated with treatment-seeking behavior.

Effect of endothelin receptor antagonists (BQ-485, Ro 47-0203) on collagen deposition during the development of bleomycin-induced pulmonary fibrosis in rats

Previous evidence suggests a role for endothelin-1 (ET-1) in the pathogenesis of pulmonary fibrosis. To determine if ET-1 regulates collagen deposition in pulmonary fibrosis, we examined the effect of the non-selective ETA and ETB receptor antagonist bosentan (Ro 47-0203), and a selective ETA receptor antagonist, BQ-485, on collagen deposition during the development of bleomycin-induced pulmonary fibrosis in rats. Lung collagen content, derived from measurements of hydroxyproline and expressed as mg collagen/lung, was increased in the bleomycin-treated animals by day 7 (bleomycin, 22.88+/-1.46; control 18.50+/-0.98; P<0.05), continued to increase up to day 14 (bleomycin, 38.80+/-2.17; control 22.57+/-0.77; P<0.001) and then remained constant to 21 days. Daily treatment by gavage with bosentan (100 mg/kg) did not prevent the increase in collagen deposition induced by instillation of bleomycin at any of the times measured. Continuous administration of BQ-485, by subcutaneously implanted minipump (7.5 mg/day), also failed to prevent the bleomycin-induced collagen deposition at 14 days. These findings suggest that ET-1 does not modulate collagen deposition during the development of bleomycin-induced pulmonary fibrosis. Further studies are required to assess whether endothelin receptor antagonists modulate other components of the fibrotic response or play a role in man.

Posttraumatic stress disorder and comorbidity in Australian Vietnam veterans: risk factors, chronicity and combat

OBJECTIVE

The objective of this study was to examine the relationship between combat-related posttraumatic stress disorder (PTSD) and comorbid DSM-III-R psychiatric diagnoses to determine commonalities in risk factors, relative onsets and the role of combat exposure.

METHOD

An epidemiological cohort study using standardised psychiatric, social and health interviews was undertaken with a national random sample of male Australian Army Vietnam veterans. Interviews and searches of military records yielded risk factors for PTSD, which were examined for association with each psychiatric diagnosis. Relative onsets of PTSD and each Diagnostic Interview Schedule diagnosis were compared. Comorbidity odds ratios were adjusted for combat exposure effects using logistic regression, and the relation between each diagnosis and combat was assessed after controlling for PTSD.

RESULTS

Commonality of risk factor profile was evident for several diagnoses, and for many their onset preceded PTSD onset. Combat was independently related to only a few diagnoses after controlling for PTSD, and PTSD remained strongly associated with several conditions after controlling for combat exposure.

CONCLUSIONS

The analysis suggests that the disorders that may constitute risk factors or vulnerabilities for PTSD comprise depression and dysthymia, antisocial personality disorder, agoraphobia and simple phobia, while those that may be consequent on PTSD are panic and generalised anxiety disorder, drug use disorders and somatoform pain disorder. Alcohol and drug use disorders and social phobia may have a mixed aetiology, while obsessive-compulsive disorder may be serendipitously related to PTSD through an association with risk of combat. Gambling disorder is unrelated.

Risk factors for posttraumatic stress disorder in Australian Vietnam veterans

OBJECTIVE

The aims of this paper are to determine the risk factors for combat-related posttraumatic stress disorder (PTSD) and to examine the relative contribution of pre-military factors, pre-trauma psychiatric diagnoses, military factors such as combat posting, and combat and casualty stress exposure.

METHOD

An epidemiological cohort study using standardised psychiatric, social and health interviews was undertaken with a national random sample of male Australian Army Vietnam veterans. Multivariate logistic regression was used to examine the relative contribution of factors derived from interview and from military records in four categories: pre-enlistment circumstances including home life, education, major life stress; pre-Vietnam psychiatric diagnoses; military experiences before and during Vietnam; and combat and stress experiences.

RESULTS

Of the 128 data items examined, significant associations were found for 39, in addition to combat stress. Pre-enlistment items accounted for about 3% of the deviance towards PTSD diagnosis, pre-enlistment psychiatric diagnosis about 13%, military variables about 7% and combat stress about 18%; all factors together accounted for 42%.

CONCLUSIONS

The results confirm that pre-military and military variables make only a small but significant contribution to PTSD either alone or after controlling for combat stress; that psychiatric diagnoses of depression, dysthymia and agoraphobia make strong contributions to PTSD; but that combat stress makes the largest contribution even after controlling for the effects of other variables. Psychiatric diagnoses and combat stress appear to be independent in their effects on PTSD.

Variations in living donor graft rates by dialysis clinic: effect on outcome and cost of chronic renal failure therapy

OBJECT

Examination of nephrology practice variations in living donor renal grafts to determine their influence on organ supply, quality, and cost of chronic renal failure therapy.

MATERIALS

Saskatchewan chronic dialysis, cadaveric, and living donor renal grafts in 1983-1994 inclusive.

RESULTS

Saskatchewan has three dialysis (I, II, III) and one transplant clinic. In the period the renal graft incidences/million population by these dialysis clinics by organ source were; Cadaveric: 23.1, 23.2, 21.1 (p = ns). Living: 5.4, 21.7, 8.3 (I or III vs II p < 0.000, I vs III p < 0.061). Total: 28.7, 44.7, 29.4. Living donor series A is 79 grafts in patients under age 60 with primary renal disease. Series B is 20 grafts in patients with secondary renal disease or over age 59. Series A ten-year actuarial patient survival is 92% and B 44%. Series A ten-year actuarial graft survival (including regrafts) is 77% and B 39%. Rehabilitation rate in patients with functioning grafts is 88.5%. Province-wide extension of the Clinic II living-donor graft rate in 1983-1994 would have produced 160 more renal grafts or 59% of those receiving chronic dialysis in 1994. The annual maintenance for a graft with the initial grafting cost taken over five years was $10,825 and the dialysis cost $40,100.

CONCLUSIONS

(1) nephrology practice variations caused a 2.5-4.0-fold difference in living donor renal graft rates, indicating patient education by the attending nephrologist influences the living donor transplantation rate, (2) with such education the combined living donor and the cadaveric organ supply virtually meets graft demand, (3) living donor renal grafts yield a better quantity and quality of life and better cost control than dialysis with their annual cost being one-quarter that for dialysis.

Help-seeking in Vietnam veterans: post-traumatic stress disorder and other predictors

This study investigated factors predicting help-seeking from the Department of Veterans' Affairs (DVA) by Vietnam veterans. Data used were from a national Australian survey of Vietnam veterans' health (n = 641) conducted between July 1990 and April 1993. The survey involved current clinical assessments and retrospective questionnaires, supplemented with health and service records retrieved from the DVA and Army personnel files. Measures included the 1989-90 Australian Bureau of Statistics Health Survey questionnaire, and mental health, sociodemographic and operational deployment history questionnaires. For both current and lifetime diagnoses of post-traumatic stress disorder, a third of the veterans with the disorder had never obtained any health care entitlement from the DVA. Other than physical and mental problems, which accounted for the greatest proportion of the help-seeking odds, significant factors predicting help-seeking included factors such as: predeployment personality, combat exposure, the veterans' own attitudes towards their deployment, experiences during deployment, experiences during repatriation and membership of ex-service organisations. These findings on how post-traumatic stress disorder and other health problems relate to help-seeking patterns could help in developing prevention and care programs for stress disorder.

Surviving the war zone experience: preventing psychiatric casualties

This paper describes a conceptual framework for the development and evaluation of stress-prevention programs for military personnel. In recognition of the diversity of stressors present within a war zone, we propose that an effective prevention program must operate on two levels if it is to deal with the effects of war zone exposure. Prevention programs must target (1) the occupational and/or traumatic stressor(s) within the war zone and (2) the ensuing post-exposure behaviors. A case study is presented to illustrate some of the key prevention issues for military personnel.

The pathogenesis of pulmonary fibrosis: is there a fibrosis gene?

Interstitial fibrosis is seen in the lung in response to a variety of insults, and often appears stereotypical in terms of its clinical and pathological features. However, exposure to a known aetiological factor does not always lead to fibrosis. For example in bleomycin-induced pulmonary fibrosis, a wide variation in response is seen both in humans and in animal models, which is not completely accounted for by known risk factors. These observations and the existence of a number of familial forms of lung fibrosis suggest a genetic predisposition. Current hypotheses concerning the pathogenesis of pulmonary fibrosis propose an initial stage involving the influx of inflammatory cells into the interstitium. These cells, together with activated resident cells are then thought to release polypeptide mediators that stimulate the fibroblast proliferation and matrix protein synthesis typical of these disorders. Genetic influences could have an important role in regulating a number of these events, altering the immunological response to injury or modulating collagen metabolism in the lung. However, despite recent advances in molecular genetic techniques, there have been few human studies to date. Most have concentrated on genetic loci with a high degree of polymorphism such as the human leucocyte antigen (HLA) system and yield conflicting results. Others offer tantalising but as yet, incomplete insights into the mechanisms involved. Defining the genetic abnormalities underlying both the familial forms of pulmonary fibrosis and the variations seen in response to lung injury should enhance our understanding of the pathogenic processes and help to focus research in this area.

Australian Vietnam veterans: factors contributing to psychosocial problems

OBJECTIVE

The objective of the present paper is to present comprehensive models of the current psychosocial morbidity of Australian Vietnam veterans. Seldom has research in this area attempted to 'untangle' direct and indirect influences on current functioning via possible pre-army, Vietnam and homecoming pathways.

METHOD

The Australian Vietnam Veterans' Health Study gathered data on a sample of 641 veterans throughout Australia drawn randomly from army Vietnam tour lists of the era. The data arose from interview and army records of the era, and fall into four temporal categories: pre-army, Vietnam service, homecoming after Vietnam, and current state. Path analysis models of the veterans' current psychological morbidities and social wellbeing are used to identify direct aetiological influences of earlier era constructs on current state, free of confounding by indirect (often selection) effects.

RESULTS

Our results indicate that psychological morbidity (particularly posttraumatic stress disorder) is largely influenced by combat and poor homecoming experiences, although pre-military characteristics do play some direct roles in symptomatology. Social dysfunction measures show smaller effects of the Vietnam War, which may be accounted for by an indirect association with Vietnam-related psychological morbidity. Some social measures show evidence of compensatory influences of combat, high combat leading to social dysfunction because of morbidity, but simultaneously being associated with healthier social disposition (possibly because of increased exservice activity).

CONCLUSIONS

For Australian Vietnam veterans, combat-related and homecoming effects persist on a range of psychosocial endpoints 20-30 years after exposure. These effects are not explicable in terms of veterans pre-Vietnam characteristics.

Interviewer effects on epidemiologic diagnoses of posttraumatic stress disorder

In an epidemiologic study of 641 interviewed subjects in the Australian Vietnam Veterans Health Study, three diagnoses of Vietnam combat-related posttraumatic stress disorder (PTSD) were obtained: lifetime prevalence using a variant of the Diagnostic Interview Schedule and lifetime and current (1-month) PTSD prevalence using the Standardized Clincical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Third Revision. Prevalence estimates using the Standardized Clinical Interview varied according to interviewer characteristics (female vs. male, clinician vs. nonclinician) but not for the Diagnostic Interview Schedule. The authors use a simple variant of logistic regression to distill estimates of two informative parameters characterizing interviewers' judgments: severity threshold (related to the individual interviewer's criterion of "caseness") and reliability (related to degree of classification error of the individual interviewers). Examination of these estimates shows that female clinicians adopted lower severity thresholds for diagnosis of PTSD than other interviewers and hence had higher prevalence estimates while being relatively reliable in their judgments. Examination also shows that nonclinician interviewers can perform at least as reliably as clinicians. The Diagnostic Interview Schedule measure of PTSD was not moderated by these interviewer aspects. This use of threshold and reliability parameters is offered for routine use in epidemiologic field studies to examine potential interviewer effects.

The Australian Vietnam Veterans Health Study: III. psychological health of Australian Vietnam veterans and its relationship to combat

BACKGROUND

Self-reported psychiatric status of Australian Vietnam war veterans was determined 20-25 years after the war and its relation to combat was investigated.

METHOD

A simple random sample of Australian Army Vietnam veterans was interviewed nationally using standardized interviews and self-completion tests to assess the prevalence of lifetime and current psychiatric illness and its relationship to combat. Army records were used to extract data on the cohort for use in regression-based adjustment for non-response.

RESULTS

The conditions mainly affecting the Australian veterans were alcohol abuse or dependence, post-traumatic stress disorder, somatization disorder were significantly related to combat exposure but not with posting to a combat unit. Less than half of the current one-month diagnoses were related to combat, possibly because of low power conferred by the relative rarity of these conditions.

CONCLUSIONS

The results confirm a range of psychological problems in former warriors may linger 20 or more years from their war exposure and may be directly affected by exposure to war trauma.

The Australian Vietnam Veterans Health Study: II. self-reported health of veterans compared with the Australian population

BACKGROUND

Self-reported physical health status of Australian Vietnam veterans was determined 20-25 years after the war and its relation to combat was investigated.

METHOD

An epidemiological cohort study of a simple random sample of Army veterans posted to Vietnam between 1964 and 1972 was conducted with personal interviews using the Australian Bureau of Statistics Health Interview Survey questionnaire to compare veterans with the Australian population and a 21-item combat exposure index used to measure the relationship of combat to physical health.

RESULTS

Veterans reported greater health service usage and more recent health actions than population expectations. They also reported excess health problems in almost all recent illness disease categories except endocrine conditions and cardiovascular conditions; only 6 of 37 chronic disease groups were not elevated compared to the population. Adjustment for non-response changed estimates only slightly. Combat exposure was significantly related to reports of recent and chronic mental disorders, recent hernia and chronic ulcer, recent eczema and chronic rash, deafness, chronic infective and parasitic disease, chronic back disorders and symptoms, signs and ill-defined conditions.

CONCLUSION

Combat exposure may have significantly increased reports of only some health problems. A general position to complain as a result of psychological conditions due to combat is not consistent with the lack of relationship between combat and reports of physical conditions.

The Australian Vietnam Veterans Health Study: I. study design and response bias

BACKGROUND

The Australian Vietnam Veterans Health Study was set up to examine the post-war health of former soldiers 20 or more years after service and to examine the relation of combat exposure to physical and mental health.

METHOD

A prospective cohort study of a simple random sample of 1000 male Australian Army Vietnam veterans used information gathered from Army records, from personnel interview and questionnaires. Military records were used to examine response bias by determining the differences between 641 interviewed veterans, 50 known deceased veterans and 309 non-respondents (including 48 refusers and 213 non-traceable).

RESULTS

Differences were evident between respondents and non-respondents, with logistic regression modelling pointing to pre-enlistment employment, antisocial behaviour, intelligence and post-Vietnam AWOL (absent without leave) as the most important discriminants with non-respondents performing worse. Compared to respondents, deceased left school earlier, had higher rank in Vietnam and at discharge, had a higher overall number of charges but not a higher rate overall, and were less likely to have gone AWOL. Deceased also received more casualty reports than respondents and non-respondents, were better behaved during service, and were better emotionally adjusted than non-respondents. Respondents compared with the Australian population had equivalent or better current socioeconomic status.

CONCLUSION

There seems little bias due to non-response, but deceased tend to come from and older cohort than in the other two groups.